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Biomedical subjects

N Takeuchi

Publications and source records attributed to N Takeuchi.

At least 217 records · Page 12Linked to original sources
PubMed1990

[Study on the porcelain veneer restoration. 3. Effect of various treatments of porcelain surface on the bonding strength at porcelain-resin interface].

In a previous report, observations were made on the apporopriate concentrations of hydrofluoric acid and durations of application in treating porcelain surfaces to improve the bonding strength at the porcelain-resin interface. Particular concentrations and durations were found, such as 4%, 6 min. for Supper Porcelain AAA, 8%, 6 min. for VMK 68, and 6%, 3 min. for Cosmotech Porcelain, and it was clearly shown that hydrofluoric acid treatment was the most effective treatment for porcelain-resin micro-mechanical bonding. However, because of its strong corrosive action, the use of hydrofluoric acid is very dangerous, and it must be handled with extreme care even in the laboratory. Accordingly, there is a need to find a safer and more effective way of treating porcelain surfaces, particularly in the field of interoral repairs to fractured porcelain restoratives by means of porcelain-resin micro-mechanical bonding. In the present study, 2% acidulated phosphate fluoride (APF), which corrodes the surface of porcelain restoratives, PorceLock (PL), which is a 2.5% buffered hydrofluoric acid made by DenMat Co. and a 6% hydrofluoric acid (HF) preparations were applied to the surface of porcelain specimens and the resulting effects on treated porcelain surfaces were examined by means of SEM observations and shear bonding strength tests. The following results were obtained: 1. In comparison with control specimens which were not treated with any acids or fluoride, a much higher bonding strength at the porcelain-resin interface was obtained in the specimens treated with 2% APF, PL and 6% HF. 2. Regarding to SEM observations, both of the specimens treated 6% HF or PL showed extremely micro-porous surfaces.2+ surfaces of the

Acidulated Phosphate Fluoride↗
PubMed1990

[A case of holoprosencephaly with a flat electroencephalogram].

A case of alobar type of holoprosencephaly, a severe impairment of the development of central nervous system, is presented. This is a case report of 2-month-old boy who had a peculiar physiognomy with a microcephalus and an undeveloped forehead. Echoencephalography showed a defect of almost all cerebellum and a singular ventricle accompanied with severe hydrocephalus. However, his brain stem and cerebellum could be confirmed. His electroencephalogram showed complete flat waves and failed to respond to visual evoked potential test (VEP) and auditory brain stem response test (ABR). Any chromosomal abnormalities were not found.

Echoencephalography↗
PubMed1990

[Treatment of condyloma acuminata using human lymphoblastoid interferon].

Eighteen cases of condyloma acuminata were treated by human lymphoblastoid interferon (HLBI). Seventeen were male and one was female. Five cases were recurrent cases. Except one patient, all the patients were administered HLBI by intralesional injection. Five patients were treated by single injection. Others were given 2 to 8 injections during one to 5 weeks. Total dose varied from 3 x 10(6) to 24 x 10(6) U. Of the eighteen patients, 6 showed a complete response and 3 a partial response (greater than 50% reduction in size of the lesion). In 5 of the 11 patients (45%) who were treated with a total dosage of more than 12 x 10(6) U, the lesion was completely cleared. Six patients who showed a complete response did not experience recurrent disease during the 6-month follow-up period. In conclusion, intralesional administration of HLBI for condyloma acuminata proved to be effective.

Adolescent↗
PubMed1989

Cloning and expression of a functional fucose-specific lectin from an orange peel mushroom, Aleuria aurantia.

Aleuria aurantia lectin (AAL) shows sugar-binding specificity for L-fucose. A lambda gt11 expression library was constructed from A. aurantia poly(A) RNA and screened with a polyclonal antiserum directed against AAL. An immunopositive clone carrying 1.3-kb EcoRI fragment was obtained. The fragment encoded AAL, but lacked a nucleotide sequence corresponding to the two amino-terminal amino acids. The 5'-terminal part of the fragment was replaced with a chemically synthesized DNA fragment and inserted into an expression vector to yield a plasmid pKA-1. Escherichia coli carrying pKA-1 expressed functional AAL and the recombinant AAL showed the same immunological properties as those of natural AAL.

Amino Acid Sequence↗
PubMed1989

Serotonin-induced hypoglycemia and increased serum insulin levels in mice.

The effects of serotonin (5-HT) on plasma glucose levels were studied. 5-HT above 20 mg/kg induced apparent hypoglycemia in mice. The hypoglycemic effects of 5-HT were strongly antagonized by methysergide but only partially inhibited by ketanserin. However, ICS 205-930 was without effect. This indicates that the hypoglycemia induced by 5-HT is mediated by both the 5-HT1 and 5-HT2 receptors. 5-HT also produced an increase in serum immunoreactive insulin (IRI) which was completely inhibited by methysergide and partially antagonized by ketanserin. It is suggested that the 5-HT-induced increase in IRI is elicited by the activation of the 5-HT1 and 5-HT2 receptors, which is similar to the results obtained with plasma glucose. These results indicate that the 5-HT receptors may regulate blood glucose levels by modifying the release of insulin.

Animals↗
PubMed1989

Phosphorylation of the 27-kDa gap junction protein by protein kinase C in vitro and in rat hepatocytes.

We previously demonstrated that the 27-kDa major component protein in rat liver gap junctions was phosphorylated by protein kinase C in vitro (Takeda, A. et al. (1987) FEBS Lett. 210, 169-172). In this study, we examined this further and examined the phosphorylation of the 27-kDa gap junction protein in rat hepatocytes by metabolically labeling cells with [32P]orthophosphate and using a monoclonal antibody to immunoprecipitate the protein. The in vitro phosphorylation was inhibited by monoclonal antibodies recognizing the carboxyl- (C-)terminal domain of the 27-kDa protein. Protease digestion analysis revealed that phosphorylation occurred at the C-terminal domain. In rat hepatocytes, the phorbol esters, 12-O-tetradecanoylphorbol-13-acetate and phorbol-12,13-dibutyrate, stimulated the 27-kDa protein phosphorylation, whereas 4 alpha-phorbol-12,13-didecanoate did not. 1-Oleoyl-2-acetyl-sn-glycerol also stimulated the 27-kDa protein phosphorylation. In addition, norepinephrine stimulated the phosphorylation and pretreatment of hepatocytes with staurosporine, a potent inhibitor of protein kinase C, inhibited this stimulatory effect of norepinephrine. Both in vitro and in hepatocytes, analysis of chemical cleavage of the 27-kDa phosphoprotein revealed that phosphorylation occurred mainly at a 10-kDa fragment which the antibodies recognized. These results indicate that protein kinase C phosphorylates the 27-kDa gap junction protein, not only in vitro but also in hepatocytes, at the C-terminal domain of the protein.

Amino Acids↗
PubMed1989

Turnover of proteoglycans by chick lens epithelial cells in cell culture and intact lens.

Chick lens epithelial cells were cultured on plastic and type IV collagen substrata, and the confluent cultures were labeled continuously with [35S]sulfate for 20 h. Intact lenses were also labeled in the same way. 35S-Proteoglycans isolated from those cultures were compared for their molecular sizes and glycosaminoglycan compositions. The results have shown that: 1) Proteoglycans synthesized by cells on type IV collagen were significantly smaller than those by cells on plastic. 2) Proteoglycans of intact lens showed a broad distribution of molecular size and contained a high proportion of chondroitin sulfate in the medium fraction compared to those of the two cell cultures. In order to explain such differences between proteoglycans from cultures, label-chase experiments with [35S]sulfate were done for proteoglycans synthesized. 35S-Proteoglycans isolated at each chase time 0, 2.5, and 17 h) were compared and the following results were found: 1) The cell layers of both "plastic" and "type IV collagen" cultures contained glycosaminoglycan species predominantly at each chase time rather than proteoglycans. 2) Changes in the glycosaminoglycan compositions of medium fractions of cell cultures were observed during the chase period; in medium of the "plastic" culture, proteoheparan sulfate increased with chase time, whereas in medium of the "type IV collagen" culture, chondroitin sulfate glycosaminoglycan (not proteoglycan) increased with chase time. 3) In intact lens culture, lens capsule fraction at every chase time contained a proteoglycan unique in molecular size, which was not found in cell culture fractions. 4) All fractions from intact lens cultures contained a higher content of chondroitin sulfate at every chase time than the respective fractions from cell cultures. These results suggest that adhesion of the cells to type IV collagen or lens capsule influences the degradation and secretion of proteoglycans. In addition, they can account partially for the above-described differences in molecular sizes and glycosaminoglycan compositions between 35S-proteoglycans from various cultures continuously labeled with [35S]sulfate.

Animals↗
PubMed1989

Immunolocalization of matrix metalloproteinase 3 (stromelysin) in rheumatoid synovioblasts (B cells): correlation with rheumatoid arthritis.

Metalloproteinases produced by connective tissue cells may play a key part in the destruction of joints in rheumatoid arthritis. Matrix metalloproteinase 3 (MMP-3; stromelysin) capable of degrading cartilage proteoglycans and type IX collagen and of activating procollagenase was immunolocalised in hyperplastic synovial lining cells in rheumatoid synovium, but not in the cells of normal synovium. Cells responsible for synthesis of MMP-3 have the phenotype of synovioblasts (B cells) by immunoelectron microscopy, but not of phagocytic synovial macrophages (A cells). Cultured monolayer of rheumatoid synovial cells synthesises MMP-3 only under treatment with macrophage conditioned medium. Immunolocalisation of MMP-3 in rheumatoid synovium and cultured synovial cells was possible when the specimens were treated with a monovalent ionophore, monensin. These results suggest that MMP-3 is synthesised and secreted continuously without storage from hyperplastic synovioblasts stimulated by factor(s) derived from activated macrophages present in the synovium.

Arthritis, Rheumatoid↗
PubMed1989

[Reconstructive surgery of obstructive disease of the upper urinary tract].

Efficacy of reconstructive surgery for the obstructive disease of the upper urinary tract was evaluated. Reconstructive surgery was performed in 75 units of the urinary drainage system of 72 patients between July, 1977 and December, 1987. 44 patients were male and 28 were female. The patients ranged in age 1 to 71, mean +/- S.D. being 43 +/- 14 years old. Original diseases were postoperative scar, scar due to the calculi, injury, retroperitoneal fibrosis, ureteritis, tuberculosis, amyloidosis and multiple ureteral diverticulum. The surgery consisted of ureterocalicostomy, renal descensus, descent of right renal vein, uretero-ureterostomy, ureteroneocystostomy (to the dome of the bladder), psoas bladder hitch and renal autotransplantation. Renal autotransplantation was chosen instead of ileal substitution to preserve the continuity of the urinary drainage system, when the upper urinary tract was extensively damaged. The obstructive change of the upper urinary tract improved or disappeared in 66 of 75 units. However, it persisted in 9 units, which were treated with ureterocalicostomy (wrong technics; in 4 units), ureteroureterostomy (wrong choice of the procedure; in 4 units) and autotransplantation (cessation of anti tbc drugs; in 1 unit). In 3 of these 9 units, additional reconstructive surgery was necessary. One patient who was treated with autotransplantation, died of massive bleeding from rupture of arterial anastomosis on 14th postoperative day. No other life-threatening complications were observed. Deterioration of the renal function was observed in two severely damaged kidneys which were performed autotransplantation, although the obstructive change of their urinary tract completely disappeared.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Renal autotransplantation and extra-corporeal surgery].

Renal autotransplantation with/without extra-corporeal surgery was performed in 53 patients between September, 1975 and december, 1987. Original disease was obstructive disease of the upper urinary tract in 25 patients, renovascular hypertension and renal vascular disease in 13, renal calculous disease in 12 and renal cell carcinoma in 3. Ten of the 53 patients had solitary kidneys. Three patients died on 14, 21 and 49 postoperative days of massive bleeding with disseminated intravascular coagulopathy caused by the rupture of transplant arterial anastomosis (1 patient with urinary obstructive disease) and sepsis caused by wound infection (2 patients with renal calculous disease). Two kidneys were removed on operative day and 8 postoperative days due to arterial thrombosis in 2 patients with aneurysm of intrarenal artery. The deterioration of renal function was observed in previously damaged kidneys of two patients with extensively damaged ureter. No other severe complications were observed. In 23 of 24 patients with the obstructive disease of the upper urinary tract, disappearance or improvement of the obstructive change was observed after surgery. All 5 patients with renovascular hypertension showed normo-tension without administration of antihypertensive drugs after surgery. In 3 of 5 patients with an aneurysm of the intrarenal artery, the aneurysm was removed and reconstruction of the artery was performed successfully. Two patients with arterio-venous fistula and one patient with nut cracker syndrome had no severe hematuria with bladder tamponade after surgery. Ten of 12 patients with renal calculous disease were treated successfully without residual calculi by this procedure. Three patients who had solitary kidney with renal cell carcinoma were treated successfully by this procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Gravity-dependent atelectasis. Radiologic, physiologic and pathologic correlation in rabbits on high-frequency oscillation ventilation.

The authors identify the radiologic features of progressive atelectasis induced under conditions of reduced lung volume. Control (n = 5) and experimental (n = 7) animals were placed on high-frequency oscillation (HFO) ventilation (mean airway pressure: 3 cm H2O) for 6 hours. In the experimental animals, lung volume was artificially reduced by pneumoperitoneum during HFO ventilation. Computed tomography scans and chest radiographs were obtained every hour, and arterial blood gases analyzed. No changes were detected in the control animals. In the experimental animals, in which hypoxemia developed, homogeneous opacity in the dependent lung was found on CT images, and chest radiographs showed a diffuse homogenous shadow with loss of lung volume. Study of pathologic sections from the lung showed that the roentgenographic findings represented atelectasis. The lung was divided into three zones, from dependent to nondependent regions: severe atelectasis, mild atelectasis, and normal lung. Hyperinflations eliminated atelectasis seen on the CT images and alleviated hypoxemia; however an undesirable effect that causes barotrauma also was observed.

Animals↗
PubMed1989

[A case of tracheopathia osteoplastica].

A case of tracheopathia osteoplatica in a 43-year-old man, detected incidentally at the upper gastrointestinal examination was reported. The examination showed a long segment esophageal compression from a paraesophageal lesion. CT was effective to demonstrate the typical narrowing and wall thickening of the trachea, and to demonstrate that the esophageal compression was caused by the deformed trachea.

Adult↗
PubMed1989

[On attachment].

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Humans↗